#!/bin/sh

# run from directory where this script is
cd `dirname $0`
EXAMPLE_DIR=`pwd`

# check whether ECHO has the -e option
if test "`echo -e`" = "-e" ; then ECHO=echo ; else ECHO="echo -e" ; fi

$ECHO
$ECHO "$EXAMPLE_DIR : starting"
$ECHO
$ECHO "This example shows how to use pw.x and hp.x to calculate"
$ECHO "the Hubbard U parameters for Co in CoO2 (2D system)."

# set the needed environment variables
. ../../../environment_variables

# required executables and pseudopotentials
BIN_LIST="pw.x hp.x"
PSEUDO_LIST="Co.pbe-spn-kjpaw_psl.0.3.1.UPF O.pbe-n-kjpaw_psl.0.1.UPF"

$ECHO
$ECHO "  executables directory: $BIN_DIR"
$ECHO "  pseudo directory:      $PSEUDO_DIR"
$ECHO "  temporary directory:   $TMP_DIR"
$ECHO
$ECHO "  checking that needed directories and files exist...\c"

# check for directories
for DIR in "$BIN_DIR" "$PSEUDO_DIR" ; do
    if test ! -d $DIR ; then
        $ECHO
        $ECHO "ERROR: $DIR not existent or not a directory"
        $ECHO "Aborting"
        exit 1
    fi
done
for DIR in "$TMP_DIR" "$EXAMPLE_DIR/results" ; do
    if test ! -d $DIR ; then
        mkdir $DIR
    fi
done
cd $EXAMPLE_DIR/results

# check for executables
for FILE in $BIN_LIST ; do
    if test ! -x $BIN_DIR/$FILE ; then
        $ECHO
        $ECHO "ERROR: $BIN_DIR/$FILE not existent or not executable"
        $ECHO "Aborting"
        exit 1
    fi
done
$ECHO " done"

# check for pseudopotentials
for FILE in $PSEUDO_LIST ; do
    if test ! -r $PSEUDO_DIR/$FILE ; then
       $ECHO
       $ECHO "Downloading $FILE to $PSEUDO_DIR...\c"
            $WGET $PSEUDO_DIR/$FILE $NETWORK_PSEUDO/$FILE 2> /dev/null
    fi
    if test $? != 0; then
        $ECHO
        $ECHO "ERROR: $PSEUDO_DIR/$FILE not existent or not readable"
        $ECHO "Aborting"
        exit 1
    fi
done
$ECHO " done"

# how to run executables
PW_COMMAND="$PARA_PREFIX $BIN_DIR/pw.x $PARA_POSTFIX"
HP_COMMAND="$PARA_PREFIX $BIN_DIR/hp.x $PARA_POSTFIX"
$ECHO
$ECHO "  running pw.x as:   $PW_COMMAND"
$ECHO "  running hp.x as:   $HP_COMMAND"
$ECHO

PREFIX='CoO2'

# clean TMP_DIR
$ECHO "  cleaning $TMP_DIR...\c"
rm -rf $TMP_DIR/*
$ECHO " done"

# self-consistent calculation
cat > $PREFIX.scf.in << EOF
 &control
    calculation='scf'
    restart_mode='from_scratch',
    prefix='$PREFIX'
    pseudo_dir = '$PSEUDO_DIR/'
    outdir='$TMP_DIR/'
    verbosity='high'
 /
 &system
    ibrav = 0,
    nat = 3,
    ntyp = 2,
    ecutwfc = 60.0
    ecutrho = 480.0
    nspin = 2
    starting_magnetization(1) = -0.5,
    occupations = "smearing",
    smearing = "mv",
    degauss = 0.01,
 /
 &electrons
    conv_thr =  1.d-15
    mixing_beta = 0.3
 /
ATOMIC_SPECIES
Co   58.933195   Co.pbe-spn-kjpaw_psl.0.3.1.UPF
O    15.9994     O.pbe-n-kjpaw_psl.0.1.UPF
ATOMIC_POSITIONS {angstrom}
Co   0.0000000000     0.0000000000     0.0000000000
O    1.4062895053     0.8119216244    -0.9358761640
O    1.4062895053    -0.8119216244     0.9358761640
CELL_PARAMETERS {angstrom}
  1.4062895053    -2.4357648733     0.0000000000
  1.4062895053     2.4357648733     0.0000000000
  0.0000000000     0.0000000000    15.7312126250
K_POINTS {automatic}
 6 6 1 0 0 0
HUBBARD {ortho-atomic}
U Co-3d 0.0001
EOF
$ECHO "  Running the SCF calculation for $PREFIX..."
$PW_COMMAND < $PREFIX.scf.in > $PREFIX.scf.out
$ECHO " done"


# Perform the linear-response calculation
cat > $PREFIX.hp.in << EOF
 &inputhp
   prefix = '$PREFIX',
   outdir = '$TMP_DIR/',
   nq1 = 2, nq2 = 2, nq3 = 1,
   conv_thr_chi = 1.0d-8,
   iverbosity = 2
 /
EOF
$ECHO "  Running the linear-response calculation of Hubbard U..."
$HP_COMMAND < $PREFIX.hp.in > $PREFIX.hp.out
$ECHO " done"

